In accordance with a demand for scaling of devices, the scaling of lithography has accelerated. Accordingly, a pitch required for a pattern has been smaller than a limit that can be resolved by a current exposure device (for example, an ArF immersion exposure device). In this case, one execution of lithography cannot form a pattern with a desired fine pitch. A spacer process (sidewall transfer process) is known. In a positive process where a foundation layer is processed using the spacer pattern as a mask, first, a hard mask layer is formed on a film to be processed, and then a core of a predetermined shape is formed on the hard mask layer. Next, a spacer is formed around the core, and an upper portion of the spacer is removed. Afterwards, the core is removed. By processes described above, the spacer pattern is formed. Then, using the spacer pattern as a mask, the hard mask layer is processed. Using the hard mask layer as a mask, the film to be processed, which serves as a foundation layer, is processed. Thus, a pattern is formed.
However, with the conventional spacer process, in the case where the spacer pattern is constituted of a film with comparatively small rigidity, for example, there may be a case that the spacer pattern is internally inclined toward a side where the core was present in removal of the core. If the hard mask layer is processed using the spacer pattern thus internally inclined, the hard mask layer is also inclined similarly to the spacer pattern. If the inclination is significant, the upper portion of the hard mask layer could be obstructed. Thus, formation of the inclined spacer pattern fails to form a satisfactory pattern on a film to be processed. A need thus exists for the spacer pattern that is vertically formed to a face of the film to be processed.